Pole guard



Dec. 12, 1950 D. c. HUBBARD 2,534,170

POLE GUARD Filed Aug. 8, 1949 Patented Dec. 12, 1950 UNITED? MTENT OFFICE- ApplicationiAugust s, 1919i siiarmif 1091-1 45 The pres'ent invention relatsto bol'e guards, anch is particularly nontierned with insulgtirfig gualrds ada-pted to be applied to the pqlesofhigh tension transmissionlines When-poles are being manipulated between or: adjacent energized high voltage lines to instfllbhtihdif 'a hole."

It 'heshefen" foundith'tt'creosotediiols lre especiallj? "hazeiabus ween their f are* rnriiiiiilted adjaten't" enei. giz'd highv 'vo ltaLge lines, in sorrie case's xb edifig 34,509 v c lts. A hunter or fLtal ities have resultclfroi'n accioienti Corrector the bole with. primary eondiictois "as polesare being installed? one; of meebjeet's of 'thiniiei'itioni'sf thawevision" of lain 'imp'l 'ciile d' ir'otetiiie device is adapted, to prevent eni'efgiiiid.""con6iiiizte rsi from contacting Iine poles? Anotherbbje't o'fthe nverted-ms thebrij'Qision ofan improvedprotectiv e'device" which is adla'bted l to prevent co-ntlact o-f"the'1ine' pole Wi we conductors; eitherfrom the sicieor top fand wfiich in additio'niirovides a Wide air=g'ap' t'o 'in'sure gairist creepa'ge currents or flash 'over' "frOrn the cbhdiiiitor to the poli I Another object ofthe 'inventi'b"" is themvisionof an improved polegufdf wl'i-ichjiarbv'ids an air-gab metwn the pole awe-11' li conduc'tors; to prevent flash-over "fronfthe' conduetor to the pole; and in which surface;leekageuri nts are miniin ized by providing 'lorig lea-kag'e" paths and a minimum contact arefibetvfeen an cohdu'ctor engaginethe 'giitrd ind th"en"gagenient ofjth'e guariwith the poleitself I Another object of theiniienti6nis the mmsion of an improvedpole guaruwhichfis sturdy,

capable of being col-lapsed intwa srnztll spttce, easy to-carry; and easy 130*etsSemblgcalaEbIdf economical manufacture; end fdaptedto provide safety for linemen at the highest volt'elgesiisually employed. I

Other -objects and advantages of the," intention Will be apparent from the 'followingdesriptib'n and'the' accompanying drawings, in whichsirnfild'r characters of reference" indicate sinnli'r'" partsthroughout the several views? Referring to the single sheet of antings; eccompanyingthis" sp'cifi'ritibhi v Fig. 1 is a, side elevational 'vi are pole gua d embodying th inventio'n; inSfiaL-ie dFupne pole, and she-we. adj'alcenttwo live une {conductors Fig. 2 is a top blah View ofthe"p01e guard ofFig li H Fig. 3 is a, sidefelevati onal-View; v i a Fig. '4 is a fragmentaryseotionakviewptakenthedifCtidfififthe aII'dW 5 is a fragmentary sectional-view; taken on the lilane of the IineS S' OPFig. '3,- loo-kin Theme frame nemesis" is; lTar ffofin''d with m sh g'roovela, heapex offwhichi'sroundedi t is {aria 'th'e'tiifo sides 2mm 21 "arhtfs uh cor-her poles 'bf whicfi thre *are is attached to a pole I8.

tightened about the frame members.

it is raised through the live conductors.

downwardly of the pole, past all live conductors, when the transmission line pole has its butt end resting on the ground, before it is inserted intothe hole in the earth.

Thus there is no danger at any time of the line pole coming in contact with live conductors because the live conductors will engage the insulating poles 21-39 which are carried by the vertical frame assemblies I13 and I5.

The respective poles 2'l3l are clamped to the frame members it, i by wing nuts 3|. When the two poles 27 and 28, for example, are clamped to the frame members it and Il, this provides a vertical frame assembly for engaging one side of the pole, as indicated by No. M.

The tension members I3 may consist of belts of suitable insulating fabric, such as a webbing belt impregnated with insulating and waterproofing varnish; and these belts I3 are of sufficient length to extend around the assembly when it At one end the belt is provided with a buckle 32, through which the free end 33 may pass so that the belt can be In order to prevent the belt from slipping oif the ends of certain poles, the ends of poles 21 and 28 are preferably provided with hook members 34, this memher being of substantially U shape, with one of the legs elongated to provide an attaching flange 35.

A rivet 36 passing through the attaching flange 35 and through the pole 30 secures the hook 34 to each pole 27, 28. The hooks E i are turned downwardly at the top and upwardly at the bottom. The straps are preferably attached adjacent the buckle end to one of the frames by means of suitable wood screws 37.

The method of manipulating and using the guard is as follows: The guard is applied to a line pole while the pole is on the ground and before The twovertical frame assemblies I l and I are placed opposite each other at the end of the line pole that is to be raised between the conductors.

The device is so positioned that the upper strap I2 is located beyond the upper end of the line pole; and this strap may be pulled snugly around the ends of the poles of the two frame assemblies and secured by means of the buckle 32. The

hooks then prevent the strap from sliding off the ends of the poles.

Then the second and lower strap I3 may be pulled firmly around the lower ends of the frames and buckled. This causes the unsupported ends of the guard members or poles 2'l3fl to bow inwardly slightly at the end and outwardly at the middle and applies gripping pressure to the line pole at the V-shaped notches I8.

As previously stated, the length of the guard should be such that it prevents the live conductors from engaging the pole in every position which the pole may assume while it is being installed or lifted between the live conductors.

After the line pole has been raised into position and set, it is only necessary to release the lower strap I3, spreading the two frame members I! at the bottom, which moves the upper ends of the guard poles El-30 toward each other and releases the gripping pressure of the upper strap I2.

The hooks of theframe assembly It may then be lifted sufiiciently to disengage the upper strap I2 from the frame assembly I l, thereby separating the guard into two parts, the frame assembly I 5, which carries the straps, and the frame assembly I4, which has been disengaged from the straps.

Thereafter the two frames can readily be removed from the pole by lifting the upper strap, which is still closed over the top of the pole, the lower strap I3 having been opened. The wing nuts are provided to permit easy disassembly of the frames so they can be packed or stored in a small space.

The guard may also be used upon a pole that is to be removed. In such case the top strap I2 is adjusted and buckled to provide a loop of suitable size, which is determined by trial or measurement. A precise adjustment is not required.

The two frames are then raised, and the frame with the hooks 34 is passed through the buckled upper loop or belt I2 as the lower ends of this frame are spread outward and the hooks are hooked over the belt I2. After the upper strap I2 is engaged by both frames, the guard is adjusted for proper height on the line pole; and then the lower ends are brought in toward the pole and secured on it by means of the strap I3. In some cases it may be necessary then to tighten or adjust the upper strap I2.

The present pole guards are adapted or prevent contact of the pole with live conductors. The spacing of the parts of the guard from the line pole provides an air-gap which prevents a flashover from the conductor to the pole. The contact between the guard members 21-39 and the live conductors is merely a point contact and a long leakage path is provided along the guard members to the line pole so that surface leakage currents are minimized.

When a pole guard of the present construction is employed, fatalities, which might otherwise result from accidental contact of the pole with primary conductors, may be avoided. The danger is especially great with creosoted poles; and the present invention fulfills an urgent need for a protective device for preventing energized conductors from contacting line poles.

While I have illustrated a preferred embodiment of my invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. In an insulated line pole assembly for safe installation between existing energized line con ductors, the combination of the line pole with a pair of insulatin guard units, each guard unit including a pair of wood pole engaging members of substantially rectangular shape, provided with a tapered groove having a rounded base for engaging poles of different sizes, the pole engaging members of each unit being parallel to each other and the grooves being aligned with each other, an insulating wooden pole carried by each of the outer corners of the pole engaging members of each unit, the insulating'wooden poles being of sufficient length to extend from a point below the line conductors to a point beyond the top of the line pole, and a pair of insulating straps, each strap being located to extend about the end portions of the four poles of the two frame units to draw them together and to cause the pole engaging members to clamp the line pole with a frictional engagement and clamping force sufiicient 5 to insure the fixity of the pole guard on the line pole.

2. In an insulated line pole assembly for safe installation between existing energized line conductors, the combination of the line pole with a pair of insulating guard units, each guard unit including a pair of wood pole engaging members of substantially rectangular shape, provided with a tapered groove having a rounded base for engaging poles of different sizes, the pole engaging members of each unit being parallel to each other and the grooves being aligned with each other, an insulating wooden pole carried by each of the outer corners of the pole engaging members of each unit, the insulating wooden poles being of sufficient length to extend from a point below the line conductors to a point beyond the top of the line pole, and a pair of insulating straps, each strap being located to extend about the end portions of the four poles 'of the two frame units to draw them together and to cause the pole engaging members to clamp the line pole with a frictional REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Hamer Nov. 6, 1934 OTHER REFERENCES Publication Electrical Record, Feb. 1909, page 80. (Copy in Div. 65, Patent Ofiice.)

Number 

